please help! 430 first start

[bob k. mando]

It will hover around 7-10psi idle and not pass 30psi at all (throughout rev range). It is a tad scary.

stop running the engine. now. this is extremely serious and the engine needs to be torn down immediately.

did the shop that rebuilt this claim to have experience with Buick engines? as bobc notes, the clearances on the the bearings should have been specc'ed at .002" or less for the bearings.

if you have any question at all about the clocking of the cam bearings, those also need to be double checked.

[major_mitt]

Before I take it out....

How do you check end clearance on the oil pump? could that make a difference

Would using the correct grade oil 10w30 help as some people suggest?

Is there anything else that needs to be checked in terms of tolerances on new oil pumps.

[Bob]

Here's the oil pump measurements:

http://www.teambuick.com/reference/l...files/60-b.pdf

on page 60-81

[bob k. mando]

Would using the correct grade oil 10w30 help as some people suggest?

no, absolutely not. you said you're running 20w-50 right now, putting a thinner viscosity oil in isn't going to do anything but drop oil pressure.

the kludge fix for low oil pressure is to go the other way, put in 15w-40 or 20w-50 if you can't pull enough pressure on 10w-30. and this works for any engine, not just Buick's.

what brand oil filter are you using? not Fram, hopefully?

[bobc455]

Before I take it out....

Also before you take it out, ask your machinist what he used for the main & rod bearing clearances. A quick phone call should settle this. Then report back here and let us know.

Chances are pretty good your machinist just put the oil pump together with a gasket from a gasket kit (if he even disassembled the oil pump at all). In that case, you probably have maybe 0.005" of clearance which is more than ideal but probably not causing your problems.

-BC

[Mike Connor]

I run a 1967 430 (Block code ND) in a 1971 GS that originally had a 350 and Muncie 4 speed in it and it heats up really fast, but never gets overheated. I live in Hotlanta Georgia and we can get over 100F temperatures here during the summer. There are a couple of things that contribute to this phenomenom:

1) The exhaust crossover from the heads to the intake manifold will put a lot of heat into the intake charge quickly. If you block this heat crossover, it will heat up more slowly. Secondly, there is a heat trace at the base of the carburetor if you are using the stock manifold that connects to this crossover. I threaded the riser tubes and put hex head set screws in. This also solved the exhaust leak coming from the base of the carburetor. If you block this crossover, you MUST use an electric choke on the carburetor
2) I recently had Stage 1 valves put in the stock 430 heads and the mechanic (Dave Macintosh - Cumming, Georgia who has raced big block Buicks for over 35 years) said that the shop that put the hardedned seats in 15 years ago did not do a good job of radiusing the back side of the seats causing a hot spot in the exhaust path from each cylinder - leading to a potential overheating problem. If you had a uninformed shop do this operation (install hardended valve seats) you may want to revist this if you are doing a tear down.
3) Make sure you run the 7 blade fan and not the 6 blade fan and a 4 core radiator. the 7 blade fan is hard (only seen one on Ebay in the last year)to find since it was installed on the high compression engines. The 430 stock compression is at 10 or 10.5 to 1.
4) I run a 160F thermostat
5) I run 10 degrees of initial static timing - factory standard. Your engine will run cooler if you connect the vacuum advance to manifold vacuum instead of ported vacuum - your idle speed will go up requiring adjustment. This will run your idle advance to around 20 to 25 degrees and will retard to wherever the mechanical advance (I run one light spring and one medium spring) takes it when you open the butterflys and manifold vacuum drops. I recommend using a GM HEI unit for dead on switching without the point bounce at higher RPM's (>4000) that these engines seemed to suffer from. Counter to making LOTS of power, but it will still shred the tires and the idle is smooth as glass hiding the power potential of the engine at a stop light.

Hope this helps, the only comment I have on the oil pressure is that the 10 psi with a hot engine at idle is not uncommon, but only getting to 30 psi is a concern, Your shop mave set you up a little too loose for the big crank journals.

[major_mitt]

Hi guys, sorry about taking so long to get back.

haha Fram? noway I know all about how bad those things are. I'm using Valvoline for the run in and K+N for when it's ready. Its got Valvoline 15w40 in it at the moment

Machine shop advised bearings are at .002" as a buick should be. (at least that proves they can read the info I gave them). Ive decided the gauge must be faulty or it would have blown up by now....

Ive since put about 200miles on it to start the break in process. What is the accepted run in distance for these sorts of engines?

It's running quite well at this point, obviously not giving it too much of a hard time.

Sorted overheating, came down to a dodgy fan clutch (now welded up ) and heavily retarded timing. Also external trans cooler, the 3000rpm stall converter was heating the trans up a bit.

Still noticing a hesitation around 3800rpm, what could cause this? Carb tuning? Is it reasonable to expect full rpm on stock points ignition?

Thank you so much for all ur expertise. I can't find anyone in New Zealand that know the Buick big block. The chevy guys dont get it....

[bob k. mando]

have you fixed the oil pressure issue?

[BigRivy]

It sounds as if you have welded the fan clutch to no longer free wheel. I do not think that to be a good idea. Those large 5 or 7 blade fans are not made to spin at full speed all the time. There is a small chance that they will come apart from fatigue after awhile. Not to mention the much increased load on your water pump bearings. I had a '72 Riviera that had a fan clutch lock up on me one time. It sounded like I had an airplane under the hood. You will also be throwing away several horsepower and some efficiency trying to spin that fan at water pump speed all the time. A problem made worse with 3000 rpm converter.